Wednesday, February 01, 2012

My sister is a neurologist. She's highly active in her field and is often asked by the media to comment about her particular area of expertise within the field of neurology.

It is great having a sibling who is a medical doctor. Though she and I do technically both have the title "Doctor", I have zero medical expertise, outside of some wilderness first aid, and maybe little random bits I've gleaned from various sports-related accidents and drinking the water in the wrong village during a field trip. When something medical comes up, I call my sister. She listens, humours me, and provides general advice. But if it is anything important, or that anything is not neurological, she tells me to see my family doctor, who is better equipped to either diagnose and treat the ailment, or to refer me to a specialist who can.

That's the gist of today's Wall Street Journal op-ed from 38 of us climate scientists. It was written in response to an earlier misleading op-ed about climate change by 16 scientists who were speaking far outside their field of expertise.

Do you consult your dentist about your heart condition? In science, as in any area, reputations are based on knowledge and expertise in a field and on published, peer-reviewed work. If you need surgery, you want a highly experienced expert in the field who has done a large number of the proposed operations.

The original op-ed argued that "There's no compelling scientific argument for drastic action to 'decarbonize' the world's economy". It's important to deconstruct that statement. Had the authors of that op-ed only argued against action to reduce greenhouse gas emissions, I would disagree with them, but not protest the publication of their op-ed.

What those 16 scientists did, however, was very different. They took advantage of their scientific credentials to raise questions about the evidence for climate change, using ad hominem attacks and analogies in place of math, before arguing against action to reduce emissions. Their credentials, though certainly legitimate in their fields, simply do not extend to all areas of science, just as my sister is not an expert in all areas of medicine.

Our response reminds the readers what the actual experts in the field of climate science think:

The National Academy of Sciences of the U.S. (set up by President Abraham Lincoln to advise on scientific issues), as well as major national academies of science around the world and every other authoritative body of scientists active in climate research have stated that the science is clear: The world is heating up and humans are primarily responsible. Impacts are already apparent and will increase. Reducing future impacts will require significant reductions in emissions of heat-trapping gases.

It concludes with a response to the original op-eds plea against action on emissions:

It would be an act of recklessness for any political leader to disregard the weight of evidence and ignore the enormous risks that climate change clearly poses. In addition, there is very clear evidence that investing in the transition to a low-carbon economy will not only allow the world to avoid the worst risks of climate change, but could also drive decades of economic growth. Just what the doctor ordered.

Andrew Revkin argues that with this final statement, which mixes science with economics and policy, we are speaking outside our area of expertise:

The reality for most of the signatories of the rebuttal letter is that they are more akin to medical technicians — making sure the thermometers gauging a fever are reliable — and radiologists — interpreting a CT scan — than diagnosticians prescribing the appropriate treatment.

The difference, I would argue, is twofold. First, some of the signatories to the letter actually conduct research at the interface of science (diagnosis, in Revkin's example) and policy (treatment). Second, we recommend a very general response to the diagnosis (reduce emissions) rather than prescribe a particular treatment. Certainly an X-ray technician, after seeing hundreds and hundreds of X-rays and working with doctors over the years, is justified in telling a patient "You should probably put some type of a cast on that broken leg".

I agree Russell, continuing with the analogy, that the treatment is not up to the technician. The point is that, although the treatment is not the his or her call, the technician can certainly tell that there's a broken bone which requires some type of treatment.

The medical analogy scarcely improves on reflection. Inflation may be better, for as with climate change, its impact is hard to detect at low levels- the strain can go on for decades before the economy snaps.

To compound the policy problem, fractures, like temperature changes are not fungible. The impact ( cost) of fractures varies greatly with the victim- teenagers wearing arm and leg casts are unremarkable as funerals for octogenarians who break a hip.

That elasticity of response renders many tipping point scenarios dubious. One national economy may absorb climatic punishment where another succumbs, but those who fear the climate wars devolving into real ones should recall that many borders have been as historically as mobile as moving average isotherms are on maps today .

So before invoking the fracture analogy,consider the choice between having a leg- in this case the carbon based industrial energy economy , amputated, and transferring the fracture's symptoms to posterity .

Some, unable to recall all that posterity has done for them, may elect to put more faith in future medicine than the opaque art of Bayesian climate forecasting, hoping 22nd century physicians will consider leg transplants from tissue vats as trivial , and casts as a barbarous throwback to the age of the Stanley Steamer.